opencode-extended

An opinionated fork of opencode: background subagents that don't block you, side chats that answer from context without interrupting, agents that watch things and wake you up, and diffs that stay on screen. Drop-in replacement for the opencode binary, same sessions, same keys, same config.

What you can do now

• Background subagents that don't block — spawn work with background: true and keep chatting. Completion notices land mid-conversation without breaking state or caches. No flags, no asking; background-first is the default.
• Side chat (/btw) that doesn't interrupt: ask a quick question against the current session's context in the right-hand panel and keep a follow-up conversation there while the main agent keeps working. The parent transcript is never copied: the side chat replays it as a cached prefix, so context is shared without re-uploading tokens. Runs in a hidden child session with no tools. Keys: /btw <question>, <leader>j focus/close, <leader>k new, <leader>z full screen, esc back to main.
• Steer running agents — background send (or by spawn name) drops a message into a running child at its next step boundary; status shows spend, tokens, and recent tool activity; tail reads its live transcript; kill stops it; detach is the model-callable Ctrl+B that moves a foreground task to background mid-turn.
• Children talk back — running subagents push milestones to you via notify_parent instead of you polling them.
• Monitors — monitor start watches a shell command and streams matching output lines into your session; process-group kill so orphans can't hang it.
• Cron — cron create delivers a message into a session on a 5-field schedule (one-shots supported).
• Sleep — sleep parks the agent with early wake the moment new input arrives, instead of burning a shell on sleep 300.
• Worktree isolation, agent's choice — subagents edit your working tree by default. The main agent can pass isolation: "worktree" on any task call to run that agent in a temporary git worktree instead (auto-removed when clean, path returned when dirty); an agent's config can set a default with "isolation": "worktree".
• ESC picks up queued input instead of stranding it; programmatic aborts/kills still stay dead.
• Completed diffs stay visible in the TUI when tool details are hidden — no more flash-then-gone edits.

Setup

Prerequisites: Bun >= 1.3 and git. Build takes a few minutes (embeds the web UI):

git clone -b better https://github.com/KapilSareen/opencode-extended.git
cd opencode-extended
bun install
bun run --cwd packages/opencode script/build.ts --single --skip-install
# binary: packages/opencode/dist/<platform>-<arch>/bin/opencode

Use it as your opencode (same sessions, credentials, config). Put this wrapper earlier on PATH than the upstream binary (e.g. ~/.local/bin/opencode):

#!/bin/sh
export OPENCODE_DB="$HOME/.local/share/opencode/opencode.db"
export OPENCODE_EXPERIMENTAL_BACKGROUND_SUBAGENTS=true
exec /path/to/opencode-extended/packages/opencode/dist/opencode-linux-x64/bin/opencode "$@"

(OPENCODE_DB pins the shared sessions database — dev builds otherwise use a version-derived DB filename. Auth, config, and cache are shared through the standard XDG paths.)

Make sure the shared global config names a working default model, e.g. in ~/.config/opencode/opencode.jsonc:

{
  "model": "opencode-go/deepseek-v4.1-flash"
}

Notes:

• Project-local .opencode/ directories are shared with upstream by design.
• Serving both binaries at once? Give them different ports (serve --port ...).
• The upstream binary stays wherever it was — remove the wrapper to go back.

Everyday reference

Want	Do
Run something in background	task with background: true (preferred for independent work)
Check / steer / stop a child	background status|send|kill|list|tail|detach (by task_id or name)
Get progress pushed to you	child calls notify_parent at milestones
Watch a command	monitor start with a regex pattern; stop|status|list to manage
Recurring nudge	cron create with "*/15 * * * *" + message; delete to remove
Wait for something	sleep with duration_ms (wakes early on new input)
Isolate file edits	off by default; the agent can pass isolation: "worktree" per task, or set it per agent
Background a running task yourself	Ctrl+B in the TUI
Ask a side question	/btw <question> (or <leader>j to open the panel)
Follow up in the side chat	type in the panel; Enter sends, esc returns to main
New side chat / full screen	<leader>k / <leader>z (<leader> is Ctrl+X)

Credits

All core product work belongs upstream: opencode by sst (docs, Discord). This clone's base is anomalyco/opencode. This fork only adds the orchestration and side-chat layer above. Bugs in the new surface (background, monitor, notify_parent, sleep, cron, worktree isolation, /btw side chat) are ours, not theirs.